Is the 80psi reading on the low pressure side? If so, I'd say you may be low on juice, but then again, it could be other things. Did they read the high side too? In my opinion, a manifold gauge reading is useless unless both the low & high side are read. There are all sorts of variations of low-low, low-high, high-high, high-low, etc, and any one can indicate one of a multitude of problems.

If they only read the low side, make 'um read both the low & high together and remember, ambient(outdoor) temp. afffect gauge readings.